1. Field of the Invention
This invention relates to a device that is mounted on a vibration damping object and that reduces vibration by an inertial mass actuator having an inertial mass on a side opposite from a mounting surface.
2. Description of Related Art
A related art actuator makes use of the reaction to the force applied to an inertial mass to reduce the vibration of the object. The actuator uses a permanent magnet attached via an elastic member as the inertial mass. An electromagnetic force generated by the permanent magnet and an electromagnetic coil acts on the permanent magnet. The actuator also has a sensor for detecting the force transmitted from the elastic member that supports the permanent magnet, and a sensor for detecting the velocity at the attachment point of the actuator. The actuator reduces vibration of the object based on the signals of the sensors.
However, the related art actuator requires a space for attaching the velocity detecting sensor at the attachment point, so that the size cannot be reduced. Here, for example, when the velocity at a nearby site instead of at the attachment point is detected, the frequency characteristics may be different in the high frequency bandwidth due to the difference in detecting position. In such cases vibration may be dissipated as the gain is raised due to control.